I have a first generation TE (the two channel one) that I use to run unmodified DC engines on track power before I convert them to battery RC. I usually run on the pure DC setting rather than PWC. I feed the TE with two 7.2 volt rechargeable batteries in series (14.4 volts). I leave the wire loom with the Tamiya plugs connected to the TE because I got really tired of changing blown fuses!
Question 1: Using the TE with any given engine, why does the starting throttle setting seem higher using PWC than when using straight DC. When the engine starts with PWC I then have to slow it down by backing down the throttle. I can start at that slow a speed when using straight DC and do not have to back off on the throttle. From all I have read, it should be the other way around.
I also have an original PFM Sound System (with the hardwired reverb). At time of purchase (1st one to hit the hobby shop in what (?) 1972? I was in HO operating mostly Hallmark and PFM brass engines on display layouts. The sound system had its’ power transistors replaced with higher capacity ones when the original ones burned out. I was working at Bobby Hall’s Hobby House at the time and we had a rash of the early PFM systems with bad transistors. I had many electronic experts as customers, so I never sent one back to PFM. I just drafted one of customers to analyze the problems and fix them. We never had one come back a second time and mine has worked perfectly ever since. I have never measured the actual DC maximum voltage output, either unloaded or under load, but it has always worked satisfactorily.
When I bought my first LGB engine (the 0-4-0 in the passenger set) to run around the tree for Christmas, 1972, I immediately put a PFM sound module and 3†speaker in the engine. I have run it, and other LGB engines and other Large Scale brands ever since using the PFM throttle/sound system. It has always provided enough power to run at the speeds I like with the train lengths my layouts could handle. Only one engine at a time, of course, since the chug sensing gets confused if you have more than one engine on the track at the same time.
Although I have managed to install AirWire and Phoenix sound in two Bachmann engines without burning anything up, I still manage to blow diode headlights fairly regularly. So I still don’t feel confident when it comes to the new electronics. This brings us to:
Question 2: Could I use the PFM system to power the TE?
I know I would have to be very careful to not change the input polarity from the PFM or I would blow the fuse in the TE. I will have to determine the output voltage of the PFM to make sure it doesn’t exceed the input voltage limit of the TE. The TE selector switch will have to be on straight DC. Assuming that I can satisfy those requirements, would I then get the chug generated by the PFM through the TE, without letting the magic smoke out of something?
Why would I want to do this? Although I am changing to battery RC, I have a number of engines that would suddenly have sound (chug at least) with walk around speed and direction control running them one at a time. The layout is already wired for what used to be called multiple cab control and each individual block is fully isolated (as in both rails insulated and no common rail).
This is really just a theoretical question, as the results don’t address all the benefits I get from battery RC, but I was just wondering….?
Chuck in Dallas